This invention relates to methods of electrically contacting to conductive plugs, to methods of forming contact openings, and to methods of forming dynamic random access memory circuitry.
As circuit densities increase in semiconductor devices, the probabilities of individual device components becoming grounded to other device components increases as well. In the context of memory circuitry, and in particular dynamic random access memory circuitry, a continuing emphasis is placed upon maximizing the number of memory cells which are formed over a wafer. Balanced against the concerns for maximizing efficient use of wafer real estate, are concerns associated with providing storage capacitors with desirably high storage capabilities.
This invention arose out of concerns associated with improving the usage of wafer real estate during formation of integrated circuitry. In particular, this invention arose out of concerns associated with providing improved methods of forming dynamic random access memory circuitry.
Methods of electrically contacting to conductive plugs, methods of forming contact openings, and methods of forming dynamic random access memory circuitry are described. In one embodiment, a pair of conductive contact plugs are formed to project outwardly relative to a semiconductor wafer. The plugs have respective tops, one of which is covered with different first and second insulating materials. An opening is etched through one of the first and second insulating materials to expose only one of the tops of the pair of plugs. Electrically conductive material is formed within the opening and in electrical connection with the one plug. In a preferred embodiment, two spaced apart conductive lines are formed over a substrate and conductive plugs are formed between, and on each side of the conductive lines. The conductive plug formed between the conductive lines provides a bit line contact plug having an at least partially exposed top portion. The exposed top portion is encapsulated with a first insulating material. A layer of second different insulating material is formed over the substrate. Portions of the second insulating material are removed selectively relative to the first insulating material over the conductive plugs on each side of the conductive lines to provide a pair of capacitor containers. Capacitors are subsequently formed in the containers.